title: Labile compounds in plant litter reduce the sensitivity of decomposition to warming and altered precipitation.
abstract: Together, climate and litter quality strongly regulate decomposition rates. Although these two factors and their interaction have been studied across species in continent-scale experiments, few researchers have studied how labile and recalcitrant compounds interact to influence decomposition, or the climate sensitivity of decomposition, within a litter type. Over a period of 3 yr, we studied the effects of warming and altered precipitation on mass loss and compound-specific decomposition using two litter types that possessed similar heteropolymer chemistry, but different proportions of labile and recalcitrant compounds. Climate treatments immediately affected the mass loss of the more recalcitrant litter, but affected the more labile litter only after 2 yr. After 3 yr, although both litter types had lost similar amounts of mass, warming (c. 4°C) and supplemental precipitation (150% of ambient) together accelerated the degradation of alkyl-carbon and lignin only in the more recalcitrant litter, highlighting the role of initial litter quality in determining whether the chemistry of litter residues converges or diverges under different climates. Our finding that labile compounds in litter reduce the climate sensitivity of mass loss and the decomposition of recalcitrant matrix is novel. Our results highlight the potential for litter quality to regulate the effect of climatic changes on the sequestration of litter-derived carbon.
authors.affiliation: Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA.|School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA.
authors.forename: Vidya
authors.initials: V
authors.lastname: Suseela
authors.affiliation: School of Agricultural, Forest and Environmental Sciences, Clemson University, Clemson, SC, 29634, USA.
authors.forename: Nishanth
authors.initials: N
authors.lastname: Tharayil
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts Amherst, MA, 01003, USA.
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
authors.affiliation: Department of Forestry and Natural Resources, Purdue University, West Lafayette, IN, 47907, USA.|Department of Biological Sciences, Purdue University, West Lafayette, IN, 47907, USA.|Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA.
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Dukes
mesh_terms: D002244:Carbon / Q000737:chemistry*; D057486:Carbon Cycle; D057232:Global Warming; D006812:Humic Substances / Q000032:analysis*; D008031:Lignin / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D028502:Polygonum / Q000737:chemistry; D011891:Rain; D013696:Temperature
chemical_list: D006812:Humic Substances; D002244:Carbon; D008031:Lignin
keywords: 13C NMR; DRIFT; Japanese knotweed (Polygonum cuspidatum); climate change; lignin; litter decomposition; recalcitrant